Can't get open loop idle (C5Z)

[onspeed]

I have PE set to be enabled at idle, but car won't go into open loop for some reason. It's a 2002 C5 Z06, EPS 226/230 .598/.609 111+2, LTs. Trying to run less fueling at idle since I think the LTs + overlap is throwing my WBO2 readings off, rather strong fuel smell at idle, and when using the bi-directional controls in the scanner, the car seemed to idle better and with a higher MAP pressure at ~16 afr.

What setting am I forgetting to disable? Also, if my VE table is tuned for "14.7" at idle, do I need to retune VE tables if I want to run lean at idle or can I just play with the Eq ratios? Also, even if I force open loop with the scanner, it still commands 14.68 although the associated boxes on the OLFA should be ~16. What gives?

Editor version is 2.23.

[SargeZ06]

I have PE set to be enabled at idle, but car won't go into open loop for some reason. It's a 2002 C5 Z06, EPS 226/230 .598/.609 111+2, LTs. Trying to run less fueling at idle since I think the LTs + overlap is throwing my WBO2 readings off, rather strong fuel smell at idle, and when using the bi-directional controls in the scanner, the car seemed to idle better and with a higher MAP pressure at ~16 afr.

What setting am I forgetting to disable? Also, if my VE table is tuned for "14.7" at idle, do I need to retune VE tables if I want to run lean at idle or can I just play with the Eq ratios? Also, even if I force open loop with the scanner, it still commands 14.68 although the associated boxes on the OLFA should be ~16. What gives?

Editor version is 2.23.

Set "Closed Loop Enable" to 284 in all cells.

[edcmat-l1]

Set "Closed Loop Enable" to 284 in all cells.

He's looking for open loop idle, not full time open loop.

OP, post a data log, by the way it's setup you should be in open loop idle.

[SargeZ06]

He's looking for open loop idle, not full time open loop.

OP, post a data log, by the way it's setup you should be in open loop idle.

Damn the interweb kicks my ass.

[onspeed]

Turns out it is going open loop at idle, but the "Closed Loop Fueling" status bit doesn't change when going from idle to pt. The STFTs do go to zero though. Weird thing is that with the MAF enabled, it was actually running richer at idle despite changing the OLFA and VE table. It would idle ~13.5 afr with open loop idle. Failing the MAF and changing idle VE tables got the idle AFR to ~16 as I wanted. MAF should be calibrated... I checked it last weekend and AFR error was +/- 1%, and in theory I shouldn't need to tune it again for OL idle, right?

Another strange thing is that even though I have the OL EQ ratio set to .93 lambda for the idle cells, the scanner still says it's commanding 14.68. Also, the 1200 RPM cells aren't going into open loop, although that's not a big deal since my idle is at 800, but I would think that since my PE is set for 0-1200rpm, then my STFTs for 1200rpm should all read 0, no?

I've posted a log and my config.

[Ben Charles]

onspeed, I just looked at your tune set up the PE table the same as OFLA table from 1200 and below yours is 1.0. PE VS OFLA the computer will always take the richer of the two

Yes everything below 1200 RPM should stay 0 on fuel trims.

P.S. your OFLA table takes a big jump from 58 to 68ECT, I would make that "more gradual"

[onspeed]

Oh, that makes sense. I was thinking PE table was scaling the OLFA table, rather than the stoich value.

If I command .93 lamda, do I need to retune my VE tables which were tuned for 1 lamda or will it scale it on its own?

Tune is still a WIP obviously, I'll smooth the OLFA jump, although I'm not too concerned with that because the weather here in Texas is rarely cold enough for the coolant to be 58 degrees for more than a minute or two.

Also, any reason the STFT 1200 RPM cells on the scan are not 0 even though it's set to go PE up to 1200?

[Ben Charles]

Zero out everything in PE, MAP etc. That should fix the problem

[onspeed]

The car will go to open loop now, I think. I have it in speed density and O2 switching stops, and no STFT occurs at idle, but yet it will still usually idle around 14.7 afr. I scaled the idle VE tables down 7 % so it should run leaner. On cold start it's around 16-17 AFR, once it's up to temp and I come to a red light for instance, it'll be around 14.7. Every now and then I'll see it at 15.7ish, which is where I want it. Any reason for the inconsistencies?

Going to go back to my other tune until I have time to sort it out.